Re: Beam me up - trying to get a basic understanding of GR


"Curious" <anthonyroseuk-curious@xxxxxxxxxxx> wrote in message news:1115220928.517600.180750@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> Dirk,
>
> Thanks again for your input.
> I'm ending my participation in this thread for two reasons.
> 1. Your point about raising only one question at a time is practical,
> (thanks), no matter how closely they all relate, because every one
> seems to have their own version on everything in relativity.
> 2. It seems to me that you are not really paying attention to the
> issues being raised.

I know that this is what seems to you, but you are mistaken.

> This will only lead to an ever-increasing
> multiplicity of sub-topics and confusion.

I hae the impression that it only leads to endless repetition.

> (If you are interested, here are examples:
> a. I spoke of "proving an absolute frame of reference".
> You call it babble if proven philosophically (this shows me you can't
> think logically in the empirical sense of the word)
> and relate it to proving the existence of god (an uncalled-for
> distraction, and an unverified refutation arrived by a summary
> judgement without hearing the case).

You will see - mark my words :-)

> I can't resist pointing out here that if you take the premises of a
> theory and logically prove them to lead to a contradiction then that
> theory cannot be true in its stated form.

Yes, you have pointed that out.
And I have pointed out that this will probably demonstrate
that you haven't properly understood the premises of the
theory.
You can call this prejudice of my part. I have no problem
with that. Prejudice through experience is what makes
life easy.

> That's philosophy, and it is
> as or more powerful than direct experiment.

History has shown otherwise.
To give a pertinent example: Aristotle declared that
men have more teeth than women. He wasn't into
direct experiment.

> b. I spoke of time dilation "in actual fact".
> You answered by talking about the optical illusion of perspective.

I anticipated the usual "logical contradiction" of "mutual
time dilation". Think about my example while keeping in
mind the remark I made about the way we *define and
measure* times and distances of remote events.

> (Nuff said.)

I said it 3 times now - okay, nuff is nuff.

> c. I spoke of time dilation in appearance only.

In physics, we do measurments and create models that
are capable to describe these measurements and make
new predictions that we can verify by making new
measurements.

> You then state I clearly do not know SR/GR. (You cannot see that I'm
> raising opposites (actual vs apparent), therefore I cannot believe
> both.)

But physicists don't deal in "actual vs apparent".
If that is what your are looking for, you have come to the
wrong place. But of course, you will find a great number
of crackpots who happen to be in this "wrong" place
already. They provide great entertainment :-)

> The only reason I mentioned time dilation in appearance was because of
> your earlier reply to the effect that "Time dilation does not explain
> the constancy of the speed of light. Time dilation is one of the
> consequences of the way we measure..." A 'consequence of the way we
> measure' implies that it is an illusion arising from a method.

No. It implies that it is a *consequence* arising from a
method. Physicist don't deal in illusions. And of course the
methods have a reason for having been chosen. When you
learn what the methods are, you can always try to propose
a new method, but you will have to demostrate that you
have a better one. Physicists only work with things they can
measure and that's it.

> Either
> time dilates, whether or not we measure it, or it only appears to
> dilate when we examine it from a certain point of view.

That shows your ignorance of the scientific method in
general and of basic physics in particular.
Physicists define time as what they read on their clocks.
Under certain circumstances you and I will measure
different time intervals between two (agreed upon)
events, and then we *define* that as "time dilation" - period.
Phrases like "only appearing" and "certain points of
view" and "actual vs apparent" have no business in this
context.

> Rhetorically, could you state categorically which you believe:
> a. Time actually dilates at speed
> b. Time does not actually dilate at speed.

I think you've got some words in the wrong order.
But I know what you mean.
I'm sure you can deduce my answer from the above.

> Well, thanks for your sincere input, but please know that I've had a
> sufficiency. Sorry for being blunt but I have come to believe in saying
> it like I see it when an answer is required.
> Guess you're going to have to lump me with the cranks!
> Future queries of mine will be more focussed - ta.

Try to take a -lot- of time to carefully read the FAQ.
Don't be there on one Monday.
Be there many weeks and start at the beginning...

Dirk Vdm


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